Reversal and tunability of the surface plasmon enhanced optical forces on a nanorod pair in the presence of a dielectric interlayer

TL;DR

This study numerically explores how dielectric interlayers, especially liquid crystals, can reversibly and dynamically tune surface plasmon-enhanced optical forces on a nanorod pair, offering potential for adaptive nanophotonic applications.

Contribution

It introduces a method to reversibly and dynamically tune optical forces on nanorods using dielectric interlayers, including liquid crystals, based on numerical simulations.

Findings

Dielectric interlayers modify the magnitude and direction of optical forces.

Liquid crystal interlayers enable dynamic force reversal.

Force tuning depends on interlayer permittivity and thickness.

Abstract

We investigate numerically the modification of surface-plasmon assisted optical force on a gold nanorod pair by incorporating dielectric interlayer. The frequency dependent electromagnetic forces are obtained through full-vectorial solution of Maxwell equations with a finite element solver. We obtain the common and relative electromagnetic force experienced by the nanorods with dielectric interlayers of different permittivity or thickness. In particular, we demonstrate that the use of a liquid crystal interlayer can be utilized as a dynamic tuning mechanism for the reversal of the direction of the relative force.